Pre-deployment battery power conservation for spacecraft

Abstract

Embodiments of the present disclosure are directed to techniques for autonomously transitioning a spacecraft from a power-saving state to a power-consuming state at a time after launch of the spacecraft on a launch vehicle. Because the spacecraft can autonomously detect conditions for transitioning to the power-consuming state, commands received via an umbilical connection to the launch vehicle, or detecting the presence or absence of such a connection, is unnecessary, thereby removing several technical barriers to eliminating such umbilical connections altogether. In some embodiments, low-cost vacuum detection devices that use very small amounts of power may be used by the spacecraft to detect when the spacecraft has reached an altitude suitable for transitioning to the power-consuming state.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
       1. A spacecraft, comprising:
 one or more power-consuming systems; 
 one or more sensors; and 
 a monitoring device configured to activate the one or more power-consuming systems based on signals received from the one or more sensors. 
 
     
     
       2. The spacecraft of  claim 1 , wherein each vacuum detection device includes a pressure sensing component that has an input coupled to a reference voltage source and is configured to generate an output voltage that varies based on an ambient pressure. 
     
     
       3. The spacecraft of  claim 2 , wherein the pressure sensing component includes at least one of a pressure sensitive resistor, a piezoresistive pressure sensing device, a pressure sensitive capacitor, a piezoelectric pressure sensing device, and an optical pressure sensing device. 
     
     
       4. The spacecraft of  claim 2 , wherein each vacuum detection device further includes a trigger circuit; wherein an output voltage of the pressure sensing component is provided to an input of the trigger circuit; and wherein the trigger circuit is configured to output a binary signal indicating a presence or absence of a vacuum based on the output voltage of the pressure sensing component. 
     
     
       5. The spacecraft of  claim 4 , wherein the output voltage of the pressure sensing component is provided to the input of the trigger circuit via an amplifier. 
     
     
       6. The spacecraft of  claim 4 , wherein outputting the binary signal based on the output voltage of the pressure sensing component includes outputting a signal that indicates a presence of a vacuum in response to receiving a voltage correlated to an ambient pressure of less than about one-third of an atmosphere, and outputting a signal that indicates an absence of a vacuum in response to receiving a voltage that is not correlated to an ambient pressure of less than about one-third of an atmosphere. 
     
     
       7. The spacecraft of  claim 4 , further comprising a vacuum override signal generator coupled to the input of the trigger circuit, wherein the vacuum override signal generator is configured to transmit a voltage correlated to an ambient pressure of less than about one-third of an atmosphere in response to receiving a command via an external connection. 
     
     
       8. The spacecraft of  claim 1 , wherein the one or more sensors includes at least one of a vacuum detection device, a contact switch, a vibration sensor, a wireless communication sensor, an optical sensor, and a spacecraft-to-spacecraft connectivity sensor. 
     
     
       9. The spacecraft of  claim 1 , wherein activating the one or more power-consuming systems based on signals received from the one or more sensors includes activating the one or more power-consuming systems in response to detecting that a majority of the signals received from the sensors indicate an activation condition. 
     
     
       10. The spacecraft of  claim 1 , wherein the one or more power-consuming systems includes a flight computer. 
     
     
       11. A method for autonomously activating power-consuming systems of a spacecraft, the method comprising: receiving, by a monitoring device of the spacecraft, at least one signal from at least one sensor of the spacecraft; determining, by the monitoring device, whether the at least one signal indicates an activation condition; and in response to determining that the at least one signal indicates an activation condition, activating, by the monitoring device, the power-consuming systems; and wherein the at least one sensor is a vacuum detection device. 
     
     
       12. The method of  claim 11 , wherein activating the power-consuming systems includes activating, by the monitoring device, a flight computer. 
     
     
       13. The method of  claim 11 , wherein receiving at least one signal from at least one sensor of the spacecraft includes receiving a plurality of signals from a plurality of sensors. 
     
     
       14. The method of  claim 13 , wherein determining whether the at least one signal indicates an activation condition includes determining whether a majority of the plurality of signals indicate an activation condition. 
     
     
       15. The method of  claim 11 , wherein determining whether the at least one signal indicates an activation condition includes determining whether the signal indicates that the vacuum detection device detects an ambient pressure that is below a pressure threshold. 
     
     
       16. The method of  claim 15 , wherein determining whether the signal indicates that the vacuum detection device detects an ambient pressure that is below a pressure threshold includes determining whether the signal indicates that the vacuum detection device detects an ambient pressure that is below one-third of an atmosphere. 
     
     
       17. A monitoring device for a spacecraft, wherein the monitoring device is configured to perform a method as recited in  claim 11 . 
     
     
       18. A method of launching a spacecraft into orbit, the method comprising: loading the spacecraft with one or more power-consuming devices of the spacecraft in an inactive state onto a launch vehicle; launching the launch vehicle; detecting, by the spacecraft, a condition for activating the power-consuming devices; activating, by the spacecraft, the one or more power-consuming devices; and releasing the spacecraft from the launch vehicle; and wherein the condition is detected by one or more sensors including one or more vacuum detection devices. 
     
     
       19. A spacecraft launch system, comprising: a launch vehicle; and at least one spacecraft removably attached to the launch vehicle, wherein the at least one spacecraft includes one or more power-consuming devices in an inactive state; wherein the one or more power-consuming devices of the at least one spacecraft are activated to an active state based on signals received from one or more sensors including one or more vacuum detection devices.